The present invention relates to an improvement in staplers for commercial and residential use. More specifically, the stapler of the present invention will enable the user to physically be alerted when the stapler is empty and needs refilling.
One of the disadvantages and drawbacks of the standard stapler involves determining when the stapler is empty before the staples actually run out.
During a large stapling job, the user is oftentimes surprised to discover that the stapler needs loading. Usually, this becomes evident after several papers have been stapled unsuccessfully. It has long been desirable to remedy this situation and provide a warning to the user that the stapler is empty. There has been an attempt to solve this problem in the past as evidenced by a British stapler, discovered by the applicant, in which a small window is supplied in the side of the staple magazine in which the end staples may be viewed. However, the user must continually watch the side window lest the staples run out unnoticed. This constant inspection alleviates the problem of staples running out without warning, but creates considerable problems in the efficiency of operation and convenience for the operator.
Another solution, proposed in the prior art, quite similar to the above is exemplified by U.S. Pat. No. 2,341,530 to Crosby of Feb. 15, 1944. The Crosby Patent shows a staple tacker which incorporates an indicator means to determine the exhaustion of staples within a magazine while the stapler is closed. This is also accomplished by the use of a small window or perforation in the side of the staple magazine. A red indicator or target is painted on the inner staple follower such that as the follower advances and one or more staples are left, the user will view the red indicator and realize that loading is necessary. Such a perforation is not only small, but relatively difficult to observe during the stapling process. Thus, the user must stop between each stapling action to determine whether the red indicator is showing. Constant monitoring of a side window would prove to be highly inefficient when stapling a series of multiple papers. Consequently, the user may choose to ignore an indicator of this type and simply wait for staples to be exhausted.
Another solution, similar to the Crosby Patent is shown in U.S. Pat. No. 2,973,519 to Jopp of Mar. 7, 1961. The Jopp invention is concerned with non-jamming staplers and provides a means for seeing when only a few staples remain. In this regard, apertures are provided in an apron 33 and in the staple magazine. Normally, the user sees the silver luster of the staples until diminishing staples cause the apertures to overlap whereby the user sees the black color of the magazine which will indicate that loading is required. Again, the apertures are so small and poorly located on the side that the user must take special care not to miss the warning.
In the "Bostitch" type stapler, the driver member is urged upwardly from the magazine member when a longitudinally slidable latch on the driver member is slid rearwardly out from under a sidewise projecting detent on the magazine member and located in front of the latch.
In this invention the Bostitch type stapler is provided with a similar detent but located in rear of the latch so that the latch releases by forward sliding on the magazine member. The conventional inverted U shaped staple follower has one of its legs further elongated and provided with an upstanding integral lug which strikes the latch to release it forwardly when the follower nears the end of its path. This not only releases the driver member from the magazine member to indicate exhaustion of staples, but the conventional leaf spring snaps the driver member upwardly to visually reveal the empty magazine.
If the Bostitch Type Stapler still includes the rearward sliding latch release, a flexible strand may extend from the staple follower back around the pivot pin of the stapler and thence forwardly to the latch so that further advance of the follower at the end of its path will pull the latch rearwardly toward the pivot pin to snap up the driver member and indicate refill.
The well known "Swingline" type stapler is constructed in a manner similar to the "Bostitch" stapler except that it has a coil spring connecting the staple follower to the driver member and the latch is a pin, movable in a slot in the driver member, the pin becoming latched in undercut in the magazine member, but released by longitudinal movement of the pin away from the pivot against spring tension. In this invention, when adapted to the "Swingline" construction, the staple follower also is provided with integral upstanding lug means which engages the movable pin latch to release it forwardly when the staple follower nears the end of its path, thereby releasing the driver member from the magazine member.
In any stapler structure, a window may be provided in the upper forward portion of the driver member to reveal the staples in the magazine therebelow and visually indicate exhaustion from above, rather than from the side as in the prior art.